This invention pertains to grain valves designed to divert grain into one of a plurality of chutes, and more particularly to such a valve having side walls especially designed to avoid catching of grain between the valve member and the side walls with resultant cracking of the grain.
In handling of grain either for placing the grain in storage or for removal from storage and subsequent mixing for animal feed, it may often be desirable to run the grain from a single source into a selected one of a number of chutes. Thus, when grain is to be stored and one bin is filled, it may be desired simply to run grain from the same source into a second or third bin. At such times, a simple valve to change the direction of flow of grain becomes highly desirable.
Currently there are two types of such valves: A vane or damper type valve and a pan or bucket type. The vane or damper type valve changes the direction of grain flow to either of the two outlets by directing the grain with a plate pivoted from the bottom end. The plate is pivoted to a positive stop to cover one of the two outlets. It is sometimes held to this stop by an over-center spring to ensure that when damper is in a vertical position, vibration does not dislodge the damper, thus causing it to redirect the grain. Grain flowing against the damper exerts pressure on the vane towards the stop. The problem with the vane type valve is that leakage is allowed because of imperfect fit of the vane to the valve body.
Sheet metal is frequently not quite flat and often warps in the welding process. Thus, it is difficult to fit a steel vane inside the sheet steel housing with close enough tolerances to prevent leakage. Therefore, it is common practice to undersize the vane about a quarter of an inch or more and attach to the vane a strip of flexible material such as belting which acts as a gasket between the vane and the housing. This improves the valve's ability to seal when new but since the gasket material has much less abrasion resistance than steel, the material flowing through the valve erodes the rubber gasket on the vane allowing ever increasing leakage.
A pan valve is another type of valve which is manufactured in both Y and offset style. The pan valve includes an entrance collar inserted into the top of the valve. The collar is, in effect, a spout having a discharge end somewhat smaller than the inlet. This inlet collar directs the grain into an internal V-shaped pan pivoted centrally, but not pivoted to any stop and only held in position by a spring. When the valve is set to change the flow direction of the grain, the velocity of the incoming grain or other flowable materials can be very significant if the grain has accelerated down a long spout so the impact often partially overcomes the spring tension. The strength of the spring tension also weakens with time, causing two problems. One is that slight movement of the open top pan may allow grain to leak over the back side. This is very difficult to detect and may result in excessive leakage. The second problem is that sometimes the velocity is so great and the impact so great that it actually forces the pan to turn to the wrong discharge by causing the pan to pass the center position by overcoming the spring resistance.
By my invention, I provide sidewalls fixed to the vane so that the grain is always fully enclosed in a chute and there is no movement between the vane and the walls in any part of the valve where grain is present. I also provide in pan type valve in which the curved sidewall of the chute and positive stop improves the performance of the valve.